<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <table border="1" cellspacing="10px" cellpadding="10px">
    <tr>
      <th>姓名</th>
      <th colspan="2">性别</th>
      <!-- <th>年龄</th> -->
    </tr>
    <tr>
      <td>张三</td>
      <td>男</td>
      <td rowspan="2">18</td>
    </tr>
    <tr>
      <td>李四</td>
      <td>女</td>
      <!-- <td>18</td> -->
    </tr>
  </table>
</body>

</html>